<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        html,
        body {
            margin: 0;
            padding: 0;
        }

        ul {
            list-style-type: none;
            margin: 0;
            padding: 0;
        }

        li {
            float: left;
            height: 30px;
        }

        .hello {
            height: 30px;
            float: left;
        }
    </style>
</head>

<body>
    <div>
        <ul>
            <li>
                <div class="hello"></div>
            </li>
        </ul>
    </div>
</body>

</html>